Primary macronodular bilateral adrenal hyperplasia (PMBAH) was incidentally identified in a 69-year-old woman who developed a biliary colic. She had a 30-year history of hypertension and was treated by three antihypertensive drugs. Concomitantly, one of her four sons was also referred after incidentally discover of a PMBAH. This 50-year-old man had developed, 1 year before, severe hypertension needing four antihypertensive drugs. Moreover, 2 years before, another son was also incidentally diagnosed for PMBAH through an ampulloma cure. This 49-year-old man had no hypertension but osteoporosis treated for many years.

Hormonal evaluation showed in all three patients: basal suppressed ACTH, no plasma cortisol suppression after 1-mg over-night dexamethasone suppression test and aberrant adrenal sensitivity in response to several ligands (all data will be shown on poster).

The mother underwent surgical resection of the biliary duct tumor. Histopathology is compatible with a neuroendocrine tumor. Immunostainings and genetic testing are still in progress.

PBMAH is often genetically determined and several genes have been identified, ARMC5 being the last one. Illegitimate receptor expression is observed in the majority of PBMAH. However, the associated-tumors phenotype exhibited by this family does not enter into the spectrum of the described malignancies predisposing syndromes (no hyperparathyroidism). Anyway, investigations are continued in the others children and grandchildren.

This case illustrates the phenotype variability within one family with a rare genetic cause of Cushing's syndrome and highlights the importance of a complete clinical characterization to permit phenotype-genotype correlations for a better knowledge of this disease.